pci.sys missing or corrupt

[agarwalgaurav1 0]

when I start my computer I get the message pci.sys missing or corrupt,try repair your system using repair of windows XP.

But When I inserted the setup CD,it started to load files but is not able to load Kernel Dll from the CD....and gives the error...

 

Setup cannot continue the error code is 7.

Please help

[DosFreak 2]

Run memtestx86 on your computer to test your memory.

Verify you are not overclocking your machine.

Verify that CPU/Memory is not overheating.